This prospective cohort study is designed to examine the association between blood and urine biomarkers (including genetic variants) and long-term kidney disease progression among 2000 Chinese IgA nephropathy patients with relatively normal kidney function (eGFR≥60 ml/min/1.73 m2).

Glomerulonephritis is the leading cause of end-stage renal disease (ESRD) in China, where IgA nephropathy (IgAN) is the most common primary glomerulonephritis among individuals undergoing renal biopsy. The outcomes of IgAN vary highly among individuals; some have the stable renal function for lifetime and some quickly progress to ESRD. No biomarker is widely applied to predict the outcomes in IgAN yet. Previous GWAS studies including ours have identified some susceptibility loci associated with the development and clinical features of IgAN. In addition, a few cohort studies have revealed several genetic loci related to the progression of IgAN. But, all of the reported GWAS studies were based on a case-control design, which may not provide the information about the effect of genetic variants on the progression of disease. Previous cohort studies which focused on certain specific candidate genes cannot unbiasedly explore the progression related susceptibility loci. Furthermore, there is no study that integrates the information from whole genomic loci and serum and urine biomarkers to predict the long-term progression in IgAN. Therefore, we design a relative large prospective cohort study to examine the association between blood and urine biomarkers (including whole genomic loci) and long-term kidney disease progression among 2000 Chinese IgAN patients with relatively normal kidney function (eGFR≥60 ml/min/1.73 m2).

Inclusion Criteria:

• Male or female individuals aged 14 years or older
• Patients with biopsy-proven primary IgA nephropathy
• A renal biopsy available for reviewing must include 10 or more glomeruli.
• The first renal biopsy was performed within 3 years.
• eGFR ≥ 60 ml/min/1.73 m2 (MDRD formula);
• Individuals or their legal representative who are able to understand and have voluntarily signed the informed consent form (ICF).

Exclusion Criteria:

• Relatives were diagnosed with biopsy-proven primary IgA nephropathy;
• Individuals had secondary IgA nephropathy due to diseases such as diabetes, chronic liver disease and systemic lupus erythematosus.

Patients with biopsy-proven primary IgA nephropathy